Rotatable casing hanger apparatus



p 15, 197% B. H. NELSON 3,528,86

ROTATABLE CASING HANGER APPARATUS Filed June 24, 1968 5 Sheets-Sheet 1 .Z'N VENTOE BoesvIY. A/ELSON Sept. 15, 1970 B. H. NELSON ROTATABLE CASING HANGER APPARATUS 9 F a 4 9 9 4 9 F a 0 a a 4 5 Z 9 5 n w A M m a e ammnm gay ig 2 m t 6 m m Km M v m m m. m 0 S Y I B BBY H. A/ELSON Filed June 24 1968 p W76 B. H. NELSON 3528,66

ROTATABLE CASING HANGER APPARATUS Filed June 24, 1968 5 Sheets-Shea, i5

1920 7 l l g 191 1 128 10 7' TOIQNE r.

p 15, 197 B. H. NELSON 3,528,fi86

ROTATABLE CASING HANGER APPARATUS File-c1 June 24, 1968 5 Sheets-Shae; 1

0539/ LSON wm/ KW p 5, 197m B. H. NELSON 3,528,686

ROTATABLE CASING HANGER APPARATUS I Filed June 24, 1968 5 Sheets-Sheet a INVENTOE Bases H fl EL so/v 3,528,686 ROTATABLE CASING HANGER APPARATUS Bobby H. Nelson, Houston, Tex., assignor to Vetco Offshore Industries, Inc., Ventura, Califi, a corporation of California Filed June 24, 1968, Ser. No. 739,341 Int. Cl. E21b 19/10 US. Cl. 285-18 20 Claims ABSTRACT OF THE DISCLOSURE Well bore casing hanger apparatus in which an outer hanger body supports a plurality of inner hanger bodies, one of said inner hanger bodies comprising relatively rotatable body sections enabling rotation of the casing supported thereby, and in which the packing structure is shifted into a sealed position to close an annular flow passage between adjacent hanger bodies. Such casing hanger apparatus connected to a tubular running-in string having a releasable connection with the rotatable hanger body section for effecting rotation of the casing, the releasable connection comprising a threaded connection, and lock means for preventing relative rotation of the threaded parts unless separation of the running tool from the hanger assembly is desired, or a fluid pressure operated latch mechanism and a clutch.

In the drilling of oil and gas wells at an underwater site, different casing strings are hung to protect strata that have been drilled through from the pressures and fluids which may be required or encountered at greater depths. In many cases, a special housing is provided at or near the ocean bottom to support and seal off a casing string cemented in the well bore. With a drilling rig above water and the special housing below water, there are many problems encountered in supporting a casing string, circulating fluid for conditioning the well, cementing the casing string, energizing an annular seal, testing the seal, and installing a protector which protects the seat and sealing area in the housing for the next casing hanger used in suspending another casing string to be lowered within the casing string or strings previously installed in the well bore. The problems are accentuated or made more difficult where the drilling rig is on a floating structure anchored in position, but still capable of moving up and down, from side to side, with the tide and waves.

In the cementing of well casing strings in well bores, or in previously set strings of well casing, it is desirable that, in advance of the displacement of the cement slurry, the well bore or the previously set casing will be leaned so as to remove therefrom deposits of well drilling fluids, or the like, which may accumulate thereon, so as to enhance the ultimate bond of the cement between the well bore, the previously set casing, and the inner casing string. Typically, one mode of cleaning the well bore and previously set well casing involves the utilization of so-called wall scratchers having scratch fingers projecting from the inner string of easing into scratching engagement with the well Wall or the previously set casing. Scratching of the wall surface is effected by reciprocation of the string of easing supporting the scratcher fingers. In some instances, scratcher fingers are adapted to effect the scratching action in response to rotation of the finger supporting casing string. Reciprocation of the casing string to effect the wall scratching operation is impractical where the casing hanger apparatus is situated at the bottom of a body of water, such as on the ocean floor, when the mechanism for reciprocating the casing is seated upon a floating vessel, which is subject to the wave and tide action.

States Patent ice Moreover, the casing hangers heretofore available for underwater casing hanger installations have been such that rotation of the casing cannot be accomplished.

The present invention provides casing hanger apparatus which enables rotation of the casing string supported thereby, whereby to enable the scratching of the previously set casing or the well bore, so as to enhance fluid circulation and the ultimate cement bond.

More particularly, the present invention provides casing hanger apparatus adapted to be lowered on a running-in string and landed in a supporting structure which may include a previously landed and anchored casing hanger from which is supported a larger casing string, the present casing hanger apparatus including a sectional body, one section of which is rotatable relative to the other section, the rotatable section supporting the casing string and having a releasable connection with a running-in string of pipe, so that the rotatable body section may be rotated by the running-in string, and then the running-in string may be released from the rotatable body section.

In accomplishing the foregoing, the present casing hanger apparatus also includes a sealing or packing structure adapted to be actuated into a sealed position in an annular flow pssage defined by the present casing hanger and the supporting structure therefor, the packing structure being actuatable in response to rotation of the running-in string of pipe after the connection between the running-in string of pipe and the rotatable hanger body section has been released. The releasable connection between the running-in string of pipe and the rotatable hanger body section comprises within the purview of the invention a left-hand threaded connection which is locked to prevent threaded separation of the running-in string from the rotatable body section during initial right-hand rotation of the rotatable body section with resultant right-hand rotation of the casing string supported thereby. In this combination, the packing structure is also actuatable into a sealed condition in response to right-hand rotation of the [runningin string, but the actuation of the packing structure is prevented until the threaded connection between the runningin string of pipe and the rotatable body section has been released for separation. It is also within the purview of the invention that the releasable connection between the running-in string and the rotatable body section may comprise fluid pressure actuated latch mechanism controllable by darts adapted to be dropped into the running-in string of pipe and to land within the casing hanger structure, such darts having fluid passages for allowing the application of fluid pressure from the running-in string of pipe to the pressure operated latch mechanisms whereby to effect its release on the one hand, or its engagement on the other hand.

An object of the invention is the provision of a casing hanger assembly adapted to support a string of casing in a supporting structure at the bottom of a body of water, the casing hanger apparatus being capable of being run in and set in place, as well as capable of effecting rotation of the casing string supported thereby.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of several forms in which it may be embodied. Such forms are shown in the drawings accompanying and forming part of the present specification. These forms will now be described in detail for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense.

Referring to the drawings:

FIG. 1 is a combined side elevation and longitudinal section of a casing hanger and associated apparatus installed in and in connection with a well bore underlying a body of water;

FIGS. 2a and 2b together constitute a quarter longitudinal section through casing hanger apparatus embodying the invention and landing in a surrounding hanger body or housing, the parts being illustrated in the initial condition which they occupy in lowering the apparatus from the drilling rig, FIG. 2b being a lower continuation of FIG. 2a;

FIG. 3 is a fragmentary detail view in vertical section, and on an enlarged scale, showing the releasable threaded connection between the running-in string and the rotatable casing hanger body section, the connection being locked against release;

FIG. 4 is a view corresponding to FIG. 3, but showing the releasable connection conditioned for release;

FIGS. 5a and 5b together constitute a quarter longitudinal section similar to that of FIGS. 2a and 2b, but showing the running-in string released from the rotatable hanger body section and also showing the packing means set in sealing position, FIG. 5b being a lower continuation of FIG. 5a;

FIG. 6 is an enlarged fragmentary detail view in vertical section and on an enlarged scale, illustrating the rotatable interconnection between the hanger body sections and the packing means in packed-off condition;

FIG. 7 is a view partly in vertical section, parts being broken away, to illustrate the seat protector and its connection with the packing structure with the running tool removed;

FIG. 8 is a fragmentary view, partly in longitudinal section and partly in elevation, of a modified form of the invention with the running tool releasably latched to the rotatable hanger body section;

FIG. 9 is a fragmentary detail view in vertical section showing the releasable latch mechanism of FIG. 8 released for allowing removal of the running tool; and

FIG. 10 is a horizontal sectional View as taken on the plane of the line 1010 of FIG. 8.

A typical installation of apparatus embodying the invention is illustrated somewhat diagrammatically in FIG. 1, in connection with a well bore A underlying an ocean or other body of Water and extending downwardly from the ocean floor F. A suitable base structure B is supported on the ocean floor and carries an outer casing C of relatively large diameter suspended from a casing hanger body or head D resting upon an outer seat E on the base and locked thereto by a suitable lock ring G. Disposed within the outer casing is an intermediate string of casing H extending down into the well bore and suspended from a suitable casing hanger body I resting upon a companion tapered seat K in the outer body and suitably locked thereto by a lock ring M. One or a stack of blowout preventers N are connected by means of a suitable connector P, such as a hydraulic connector illustrated in Letters Patent of the Us. No. 3,321,217, for Coupling Apparatus for Well Heads and the Like, to the head D, the blowout preventers, in turn, being connected by a suitable hydraulic or other connector R to a flexible joint S made of sections secured to a marine conductor pipe T extending to the drilling rig, which may be located on a drilling platform or on a floating vessel or structure. Another string of easing Y is disclosed in FIG. 1 as having been supported by a hanger W locked in packed-off condition in the intermediate hanger body and it is in connection with the hanging of an inner casing X by a hanger Z, for example, to which the present invention is directed.

As shown in FIG. 2a, the hydraulic connector P, which is actually secured to the outer casing hanger body D in the manner illustrated in the above-identified Pat. No. 3,321,217, includes an adapter 10 above the hanger bodies, the inner end of the adapted clamping a suitable seal ring 11 between it and the upper end of the intermediate hanger body I, this seal ring having a groove 12 receiving a seal ring retainer 13 mounted in an internal circumferential groove 14 in the coupling adapter. The intermediate hanger body I has a lower downwardly tapering seat or shoulder 15 above which is located an internal circumferential ring groove 16 containing a split inherent ly contractable lock ring 17 having an upper inner beveled surface 18. Above the lock ring groove is an internal seal surface 19 of cylindrical form, and above this seal surface is an enlarged internal bore 20 which terminates at another internal cylindrical surface 21, which may be of the same diameter as the seal surface. Above the cylindrical surface 21, the outer hanger body I has another enlarged bore 25, and above this enlarged bore, the body I has another internal cylindrical surface 26 above which is provided a suitable internal thread 27 in the hanger body by which it may be connected to a running tool (not shown).

The casing hanger apparatus W includes a body 28 having a lower hanger thread 29 connected to the casing Y suspended therebelow. This body has a downwardly facing tapered seat 30 adapted to engage the upwardly facing seat 15 in the surrounding hanger body I. Above this seat is a reduced external diameter portion 31 providing an upwardly facing shoulder 32 engageable with the lower end of the lock ring 17 when the hanger body is moved past the lock ring, during which time the latter is expanded outwardly within its internal groove 16, then contracting partially inwardly and across the shoulder 32 so as to lock the hanger body 28 in place by preventing its upward movement.

Above the lock shoulder 32 is a reduced diameter, external, cylindrical seal surface 33 which is disposed opposite the internal seal surface 19 of the surrounding hanger body I and in spaced relation therewith, when the hanger body is resting upon its companion seat. Above this seal surface 33, the hanger body has a reduced external diameter portion 35 provided with a right-hand thread 36 to which is adjustably and threadedly secured a packer actuating sleeve 37 having an internal thread 38 meshing with the right-hand thread 36. This packer actuator sleeve supports and is employed to exert an axial force against a pack-off assembly 39 so as to shorten the latter and compress it between the opposed sealing surfaces 19, 33, as shown in FIG. 2b.

This packer actuating sleeve 37 and its actuation to effect movement of the pack-off assembly 39 into the annular space between the sealing surfaces 19, 33 by means of a seat protector having means engageable in T slots 43 in the upper end of the actuator sleeve 37 are more particularly described in the pending application for United States Letters Patent, filed Oct. 23, 1965, Ser. No. 503,561, for Well Bore Casing Hanger Apparatus. Internally of the body 28 is a thread 28a for connection to a running tool (not shown), whereby the hanger W may be run into the hanger J and the tool later removed following the completion of the usual circulating, cementing, and packing off operations.

At its upper end, the reduced diameter section 35 of the hanger body 28 provides an upwardly facing shoulder 35a on which a hanger Z made in accordance with the present invention may be landed to support the inner string of casing X in concentric relation to the hanger W, with the casing string X extending downwardly through the casing string Y.

More specifically, the casing hanger assembly Z includes an outer body section 128 having a downwardly facing annular surface 130 adapted to seat upon the upwardly facing end 35a of the hanger body 28 of the assembly W, which has been previously employed to hang the casing string Y. Revolvable with respect to the body section 128 is an inner body section 129 having a lower hanger thread 129a for supporting the casing X. Bearing means 131 are interposed between opposing laterally extended annular surfaces 132 and 133 on the body sections 128 and 129, respectively, for facilitating rotation of the body section 129 with resultant rotation of the casing string X. In the illustrative embodiment, the bearing means 131 includes anti-friction Washers 132a and 133a, respectively, engaged with the faces 132 and 133 and with one another to provide radial surfaces revolvably supporting the body 129 on the body section 128.

Sealing means are provided for preventing access of well fluids or cement to the bearing means 131, such sealing means including a seal ring 134 between opposing cylindrical surfaces 134a and 13412 below the bearing means 131. and a seal ring 135 between opposing cylindrical surfaces 135a and 135b above the bearing means 131. A resilient lock ring 136 disposed in opposing annular grooves 136a and 136k in the body sections 128 and 129, respectively, between the seal rings 134 and 135 is employed to interconnect the body sections against axial separation while allowing relative rotation of the body sections on the bearing means 131, as will be hereinafter described.

The upper body section 129 has an annular sealing surface 137 adapted to oppose the annular sealing surface 21 in the hanger J to provide an annular flow passage 138 therebetween when the hanger assembly Z is seated on the previously run hanger assembly W. Above this sealing surface 137, the body section 129 has a portion 139 having an external right-hand thread 140 on which is threadedly mounted a sleeve 141 having an internal thread 141a meshing with the right-hand thread 140. This sleeve 141 is adapted to support and move axially an annular pack-off assembly 143, corresponding to the packoff assembly 39 of the hanger W previously referred to.

The actuator sleeve 141 is connected to a seat protector 142 thereabove, which has a reduced diameter portion 142a piloted within the sleeve 141. The seat protector has a plurality of circumferentially spaced radial torque pins 144 extending into inverted T-shaped slots 145 in the sleeve 141. The seat protector carries one or more external seal rings 146 at its upper portion, which are adapted to seal against the internal cylindrical surface 26 of the surrounding hanger body I, as described hereinbelow, and this seat protector is connected to a torque tube or sleeve 147 forming part of a running and actuating tool T by means of a plurality of circumferentially spaced coupling pins 148 on the lower portion of the tube disposed within companion J-slots 149 in the seat protector 142. The vertical legs 150 (FIG. 7) of the 1- slots 149 open upwardly through an upwardly facing shoulder 151 of the seat protector, the torque tube or sleeve 147 having internal splines 152 adapted to mesh with external splines 153 on the running tool mandrel 154, the upper end of which is threadedly secured to the tubular running string 155, such as casing or drill pipe, extending to the drilling rig above the body of water. A helical compression spring 156 surrounds the mandrel 154, its upper end bearing against a spring seat 157, which, in turn, bears against a retainer ring 158 suitably secured to the mandrel 154, and its lower end bearing against the upper end of the torque tube 147 and tending to urge the latter in a downward direction along the mandrel, limited by engagement of an upper flange 159 of the torque tube with an upwardly facing shoulder 160 on the mandrel. The lower portion of the mandrel has an external left-hand thread 161 meshing with a companion internal left-hand thread 162 in the hanger body section 129, and above its threads, the mandrel carries one or a plurality of seal rings 163 adapted to seal against a cylindrical inner wall 164 of the body section 129 above its threaded portion.

The running tool T, seat protector 142, and torque tube connection to the mandrel 154 are conventional in that they are the same as might be employed to run and operate the previously described hanger W.

When the hanger apparatus Z and the casing X suspended therefrom is connected to the running tool T and lowered through the marine conductor pipe S and the equipment connected thereto therebelow by means of the casing string 155 to the position illustrated in FIGS. 2a and 2b, in which the hanger body 128 rests upon its seat 35a, a by-pass circulating passage exists between the hanger apparatus Z and the surrounding hanger body 28. As shown, this by-pass communicates with the annulus 165 between the suspended casing X and the hanger W and includes a plurality of circumferentially spaced longitudinal fluid passages 166 extending through the hanger body section 128 to the annular passage 138 between the opposed seal surfaces 21, 137. Fluid can thus pass upwardly through the annular space 167 between the pack-off assembly and the enlarged bore 25 of the external casing hanger, and thence inwardly through a plurality of fluid by-pass holes 168 formed through the upper portion of the actuator sleeve 141 to the interior of the latter, then passing upwardly through an annular passage 169 between the seat protector 142 and the mandrel 154 of the running tool T, the by-pass path then continuing through an annular passage 170 between the lower portion of the torque tube 147 and the mandrel 154 which communicates through a plurality of side ports or holes 171 in the torque tube with the annulus 172 :around the latter, the fluid flow then being capable of continuing upwardly through the annular passage 173 between the mandrel 154 and the tubular running string 155 thereabove and the surrounding apparatus to the drilling rig.

The packer assembly 143 includes an upper abutment ring 174 secured to the lower portion of the threaded packing actuator sleeve 141 by means of a swivel. Such swivel includes a split snap retainer ring 175 mounted in an external groove 176 in the nut or sleeve 141 and an internal groove 177 in the upper abutment ring 174. A thrust bearing 178 is provided between the actuator sleeve 141 and the upper abutment ring 174 so that the sleeve can be rotated without rotating the ring 174. As shown, the thrust bearing includes an upper race 178a in the threaded sleeve and a lower race 178b in the upper end of the upper abutment ring, ball bearings 178 being disposed in and between these races to allow the sleeve 141 to rotate without rotating the upper abutment ring 174.

The lower end of the upper abutment ring 174 engages an initially retracted packing element ring 179 made of an elastomer material, such as rubber or a rubber-like material, the lower end of this packing ring being engaged by a lower abutment 180 which is adapted to engage an upwardly facing shoulder 181 on the hanger body section 129 below its external seal surface. The packing ring 179 and the lower abutment ring 180 are assembled to the upper abutment ring 174 by a plurality of cap screws 182 extending through the lower ring and packer ring and threaded into the upper abutment ring, the screws having heads 183 received within counterbores 184 in the lower abutment ring and adapted to engage the upper ends 185 of the counterbores.

Prior to lowering the casing hanger apparatus Z and the casing X suspended therefrom into the well bore, the casing hanger apparatus has its parts in the relative positions illustrated in FIGS. 2a and 2b in which the packing element or ring 179 is retracted and with the actuator sleeve 141 occupying its upper threaded position on the hanger body section 129, the actuator sleeve being connected to the seat protector 142 by means of the pin and T-slot connection 144, 145 and the seat protector 142 being connected to the torque tube 147 through the pin and J-slot connection 148, 149.

The lower portion of the mandrel 154 of the tool T is secured to the hanger body 129 by means of the left-hand thread connection 161, 162. In addition, the total mandrel 154 and the body section 129 are provided with means for interconnecting them against rotation of the mandrel in a right-hand direction until the mandrel has been first rotated in a left-hand direction relative to the body section 129. This means, as best seen in FIGS. 3 and 4, includes an expansible split ring 191 engaged in an annular seat 192 in the body section 129 below the left-hand thread 162 thereon. The mandrel 154 has an annular groove 193 in which the inner periphery of the ring 192 is disposed, this groove providing an upper shoulder 194 and a lower shoulder 195. Rotation of the mandrel 154 in a right-hand direction relative to the body section 129, which should ordinarily tend to thread the mandrel upwardly in the left-hand thread connection 161, 162, is prevented by engagement of the shoulder 195 with the ring 191 which is anchored in its seat 192. Thus, rotation of the mandrel 154 to the right will cause rotation of the body section 129 to the right on the bearing means 131 relative to the body section 128, thereby also effecting rotation of the casing string X. Such rotation of the body section 129 causes rotation of the casing string X relative to the casing string Y and in the Well bore so that the wall of the casing Y and the well bore therebelow may be scraped to permit a better cement bond, as well as improved circulation of fluid and cement. Moreover, the hazards attendant to reciprocation of the casing X are avoided.

However, when it is desired to release the running tool mandrel 154 from the body section 129, it is only necessary to rotate the mandrel 154 to the left sufficiently to cause the shoulder 194 of the mandrel to engage the snap ring 191 and force it downwardly from its seat to a location at which a space 192a below the seat allows expansion of the ring 191, as seen in FIG. 4. Thereafter, right-hand rotation of the mandrel 154 will thread it upwardly from the body section 129 for removal.

In the use of the hanger Z, the casing is lowered from the drilling rig through the equipment disposed above the ocean floor and into the Well bore A, the uppermost portion of the casing string X being secured to the hanger apparatus Z, which has its parts in the relative relationship illustrated in FIGS. 2a and 2b, and which is secured to the casing string X. The shoulder 130 on the body section 128 of the hanger Z will land on the shoulder 35a provided by the hanger W. At this time, the seat protector 142 and actuator sleeve 141 are in their upper positions relative to the body section 129. Circulating fluid can now be pumped down through the tubular running string 155 and through the apparatus, continuing on down through the casing X and then passing around its lower end or through suitable casing ports into the annulus 165 between the suspended casing string and the well bore A, and also between the casing string X and whatever previously set casing string is surrounding it. The circulating fluid flows upwardly through the body passages 166 and through the annular passage 138 between the internal and external seal surfaces 21, 137, flowing upwardly around the packing assembly 143 and also upwardly between the packing assembly and the threaded portion 139 of the hanger body, continuing upwardly through and around the actuator sleeve 141 to a position above the hanger body section 129. Fluid will pass from the annular space 167 externally of the packing assembly through the by-pass holes 168 in the sleeve 141 for upward movement through the annular passage 169, 170 between the seat protector and mandrel 154, as well as between the torque tube 147 and mandrel, discharging through the torque tube holes 171 into the annulus around the torque tube, continuing upwardly through the annulus 173 around the mandrel 154 and the running string 155 to the drilling rig. During this circulation, the running string 155 may be rotated, as previously described, to effect scratching of the previously set casing and/or the well bore in which the casing X is disposed.

The circulating fluid can be followed by the pumping of a suitable charge of cement slurry down through the running string 155, the apparatus Z and the suspended casing string X. This charge of cement may have an upper cementing plug (not shown) at its upper end, which will slidably seal along the tubular running string 155 and then pass downwardly through the mandrel 154 into the casing string X, the cement then moving upwardly through the annulus around the casing string to the desired height, in a known manner, the fluid in advance of the charge of cement slurry passing upwardly through the bypass path through and around the casing hanger apparatus Z.

After the cement has been displaced around the casing X, the running string 155 and the mandrel 154 are rotated, the rotation of the mandrel being transferred through the torque sleeve 147 to the seat protector 142 and from the seat protector to the packer actuator sleeve 141 to thread the latter in a downward direction along the casing hanger body section 129, and thereby move the packer assembly 143 downwardly along the body section 129 and the surrounding hanger body I. At the same time, rotation of the mandrel 154 is effecting its unthreading from the hanger body section 129, because of the left-hand thread interconnection 161, 162 therebetween. Before the lower abutment of the packing assembly 143 reaches the body shoulder 181, the mandrel 154 will have been unscrewed completely from the hanger body section 129, whereupon rotation of the casing string 155 and the mandrel can continue to cause the downward threading of the actuator sleeve 141 and the shifting of the packing assembly 143 downwardly until the lower abutment 180 engages the body shoulder 181, at which time the retracted packing sleeve 179 is disposed between the internal and external seal surfaces 21, 137. A continuation of the rotation of the running string 155 and mandrel will effect a continued downward shifting of the actuator sleeve 141 along the body section 129, moving the upper abutment 174 toward the lower abutment 180, shortening the packing sleeve or ring 179 and expanding it outwardly and inwardly into firm sealing engagement with the internal and external sealing surfaces 21, 137 on the outer and inner hanger bodies J, 129 (FIG. 6). A sufficient torque is imposed on the apparatus to insure the firm sealing of the packing sleeve 179 against its companion surfaces. However, it is to be noted that during the entire rotation of the actuator sleeve 141 on the hanger body, the torque is not trans mitted to the packing structure 143 so that no twist is imparted to the latter, but only an axial compressive force in effecting its pack-off against the inner seal surfaces.

It is to be noted that following the complete unthreading of the mandrel 154 from the hanger body 129, its seal rings 163 still maintain a sealed relationship with the internal body surface. Accordingly, the effectiveness of the packed-off seal 143 can now be tested with all of the apparatus remaining in place. A suitable pressure is imposed on the fluid in the annulus 173 surrounding the tubular running string 155, as, for example, by closing a blowout preventer N thereagainst and then subjecting the fluid in the annulus below the blowout preventer to adequate pressure. If no pressure loss occurs, assurance is had that the seal is effective. The fact that the mandrel is still sealed against the anchor body, as disclosed in FIG. 6, will prevent fluid from passing between the mandrel and the hanger body. If a leak is detected, which is determined to be due to the packing 179, an additional compression of the packing sleeve 179 can be undertaken by turning the running string 155 and the mandrel 154, which will effect an additional downward threading of the actuator sleeve 141 along the anchor body 129.

Assuming the seal does not leak, the running tool T can now be disconnected from the seat protector 142 merely by partially turning the running string 155 to the right to be assured that the torque tube pins 148 are disposed against the ends of the J-slots 149 and in alignment with their vertical legs 150, whereupon the tubular running string 155 is moved upwardly to move the pins 148 out of the J-slots, which permits the running tool T to be removed from the casing hanger apparatus Z and elevated through the equipment thereabove to the drilling rig, the parts of the hanger apparatus then being in the position illustrated in FIG. 7, with the seat protector 142 in place and with an effective pack-off existing between the hanger body section 129 and the hanger body I or other device therearound. At this time, it is to be noted that the seat protector 142 will have its seal rings 146 in sealing engagement with the cylindrical surface 26 at the upper portion of the surrounding hanger body J, as seen in FIG. a.

When the seat protector 142 is no longer required, it is easily removed by lowering a suitable retrieving tool on a running string. This retrieving apparatus may be of the type disclosed in Letters Patent of the United States No. 3,350,130, for Well Bore Running-In and Retrieving Tool. This tool becomes coupled to the seat protector 142, as by latching under the shoulder 151 in an internal groove 151a in the upper portion of the seat protector, with suitable pins entering the J-slots 149 so as to be coupled to and transmit torque to the seat protector. The retrieving tool (not shown) can then be appropriately turned by turning the running string to turn the seat protector 142 relative to the packing actuator sleeve 141 and align the torque pins 144 with the vertical legs of the inverted T- slots 145, which will then allow an upward pull to be taken on the apparatus to shift the pins 144 from the T- slots and thereby effect a full disconnection of the seat protector 142 from the actuator sleeve 141, the seat protector then being withdrawn with the running string and tool to the drilling rig above the body of water.

While no locking means has been disclosed for holding the hanger assembly Z seated upon the hanger assembly W therebelow, in the illustrative embodiment, it will be appreciated that, if desired, such locking means may be employed. For example, a lock ring, such as that designated 17, for holding the anchor assembly W on the seat may also be employed to engage the hanger body sec tion 128 to hold the same against upward movement. Depending on the size of the casing supported by the casing hanger and the length of the casing string, the use of such locking means may be optional.

Referring now to FIGS. 8-10, a modified construction is illustrated for effecting rotation of the upper body section 129 relative to the lower body section 128 of the hanger assembly Z. In this modified construction, the upper extremity of the body section 129 is provided with a suitable number of upstanding lugs 200 and intervening spaces 201 adapted to receive spaced torque lugs 202 provided on a modified running tool T. Otherwise, the hanger assembly Z and its relationship to the body I is the same as that previously described, the assembly Z including a packing ring means 143 adapted to be actuated into sealing engagement between the cylindrical sealing surfaces 21 and 137 provided between the body I and the hanger section 129, respectively. The actuator sleeve 141, as in the previously described embodiment, is threadedly connected to the body section 129 for effecting actuation of the packing means 143. Likewise, the hanger body section 129 is rotatably supported on bearing means 131 for rotation relative to the lower hanger body section 128.

In this modification, the running tool T includes a tubular body 203 having the above-mentioned lugs 202 there on. Depending from the body 203 is an annular flange 204 which is externally threaded at 205, and internally threaded at 206, the flange having a downwardly extending cylindrical section 207. Threadedly connected to the threads 205 is an annular body 208 having a cylindrical outer wall 209 adapted to seat within the bore 210 within the hanger body section 129. Threadedly connected to the threads 206 of the body flange 204 is an inner annular member 211 having an outer ring seal 212 with the inside surface of the extension 207 of the flange 204. The annular members 208 and 211 define therebetween an annular piston chamber 213 in which is reciprocably disposed an annular piston 214 having a ring seal 215 with the outside wall of the annular member 211. This piston 214 is provided on an elongated sleeve 216 which is reciprocably disposed at one end in an annular gap 217 defined between the annular member 208 and the portion 207 of the flange 204. At its other end, the sleeve 216 is disposed about an outer cylindrical wall 218 of the member 211, a seal ring 219 being provided therebetween. An annular space 220 is defined between the lower extremity of the annular member 208 and an annular flange section 221 of the member 211. In this annular space 220 is a plurality of circumferentially spaced latch dogs 222 (see FIG. 10) held in spaced relation by a spacer ring 223. Each dog 222 is provided with a nose 224 adapted to project outwardly from the space 220 into an annular groove 225 formed within the hanger body section 129, when the tool body or mandrel 203 is disposed within the hanger section 129, as shown in FIG. 8, and when the sleeve 216 is in a downward position at which the lower end 216a of the sleeve 216 is engaged with the dogs 222 to hold the noses of the dogs outwardly. It is apparent that with the tool T engaged in the body section 129 of the hanger assembly Z and when the dogs 222 are in their outwardly projecting positions, the tool T is effectively latched to the hanger body section 129 with the lugs 202 of the tool engaged between the lugs 200 of the hanger section 129. Thus, the hanger assembly Z is connected to the tool T so as to be run into place on the running-in string 155, and, in addition, the hanger section 129 may be driven rotatably in response to rotation of the running-in string 155. Thus, the casing string supported by the hanger section 128 may be eifectively rotated to scratch the surface of the well bore or the previously set casing string, as previously indicated.

In order to apply fluid pressure to the piston 214, either to hold the sleeve 216 in the position of FIG. 8 or to move the sleeve upwardly to the position of FIG. 9, the annular member 211 is provided with vertically spaced passages 230 and 231, respectively, leading to the chamber 213 above and below the piston 214. Inasmuch as the annular areas of the piston 214 exposed to pressure at opposite sides thereover are equal, the piston 214 will normally remain in a fixed position unless its position is purposely changed by the application of differential pressure.

Means are provided for applying differential pressures to the annular piston 214 to shift the same in either axial direction and such means may comprise a first dart D1 (FIG. 8) and a second dart D2 (FIG. 9). Each of the darts D1 and D2 comprises an elongated body 235 having at its upper end a neck 236 provided with a fishing head 237. These darts are adapted to be introduced into the running-in strong at the top of the well and to travel downwardly through the running-in string, entering a bore 238 defined by the annular member 211 connected to the tool body 203, there being within this bore 238 a stop shoulder 239 which will arrest downward movement of the darts D1 and D2. The dart D 1 has a fluid passage 230a leading downwardly therethrough and laterally for communication with the passage 230 leading to the chamber 213 above the piston 214. A second passage 231a is provided in the dart D1 leading from below the dart upwardly and then laterally for communication with the passage 231 leading to the chamber .213 below the piston 214. The dart bodies preferably closely seat within the bore 238 so as to provide an effective seal, and, therefore, fluid pressure supplied to the passage: 230a of the dart D1 through the running-in string 155, as shown in FIG. 8, will cause the application of a pressure above the piston 214, forcing the piston downwardly whereby to effect outward shifting of the latch dogs 222. When it is desired to release the tool from the latched condition of FIG. 8, then the dart D2 will be employed. This dart has a passage 231b leading downwardly and laterally for communication with the passage 231 below the piston 214, and a second passage 23% which leads upwardly and laterally for communication with the passage 230 leading to the chamber 213 above the piston 214. Thus, when the dart D2 is in place, as seen in FIG. 9, and fluid pressure is supplied through the running-in string 155, such pressure will act to shift the piston 214 upwardly, removing the lower end 216a of the sleeve 216 from behind the latch elements or dogs 222 so that the latter are free to move inwardly from the groove 225 in the hanger body section 129. This groove 225 may have an upper beveled wall 225a adapted to forcibly cam the latch dogs 222 from the grooves 225 when an upward force is applied to the tool T.

In the use of the tool T of the embodiment of FIGS. 8-10 to run and rotate the casing hanger assembly Z, it will be noted that the assembly will be run into the well and landed in the previously set casing hanger W, and, thereafter, the running-in string 155 may be rotated in either direction to effect the scratching of the previously set casing and/or the well bore. During rotation of the running-in string 155 and circulation of a flushing fluid, the bore 238 within the tool will, of course, be free of any dart so that the circulation of fluid occurs through the bore 238, thence downwardly through the casing string supported by the hanger assembly Z and upwardly about the outside of the hanger assembly, as previously described. Following the circulating and scratching operations, the dart D2 will be placed in the running-in string 155, and when the dart D2 seats in the bore 238, the running tool T will be released and may be retrieved from the well.

Thereafter, suitable actuator means may be employed to engage the outer sleeve 141 to effect rotation thereof and downward movement and actuation of the sealing or packing means 143. A tool for effecting actuation of the sleeve 141 may be as described in the above-mentioned Letters Patent of the US. No. 3,350,130. Such a tool may also be employed to remove the outer ring 141 and interconnected packing means 143 from the rotatable hanger body section 129 of either of the above described embodiments of the invention, in the event that replacement of the packing means is necessary.

From the foregoing, it will now be apparent that the present invention provides a casing hanger apparatus and running tool therefor, whereby the hanger assembly and a string of casing supported thereby may be easily run into a supporting structure located at the ocean floor and the running-in string may be rotated to eifect rotation of the casing relative to the previously installed casing string and relative to the well bore, so as to enable the scratching of the wall of the previously set casing and the well wall during the circulation of a flushing fluid preliminary to the displacement of a body of cement slurry into the annular space defined by the casing and previously set casing and the well bore.

I claim:

1. In well bore casing apparatus for supporting an inner string of casing in an outer string of casing supported by an outer casing hanger providing a seat: an inner casing hanger including a first body section having a portion engageable with said seat, a second body section rotatable relative to said first body section and having means for connection with said inner casing string, means for preventing relative axial movement between said sections, packing means for forming a seal between said inner and outer casing hangers, a mandrel adapted for connection to a running string, means for releasably connecting said mandrel to said inner casing hanger to permit said mandrel to be disconnected and removed from said inner casing hanger, and means for rotating said second body section relative to said first body section upon rotation of said mandrel.

2. Well bore casing apparatus as defined in claim 1, wherein said means for releasably connecting said mandrel to said inner casing hanger includes a threaded connection between said mandrel and said second body section, and said means for rotating said second body section includes releasable means for initially preventing rotation of said mandrel relative to said second body section 12 to prevent unthreading of said mandrel from said second body section.

3. In well bore casing apparatus for supporting an inner string of casing in an outer string of casing supported by an outer casing hanger providing a seat: an inner casing hanger including a first body section having a portion engageable with said seat, a second body section rotatable relative to said first body section and having means for connection with said inner casing string, packing means for forming a seal between said inner and outer casing hangers, a mandrel adapted for connection to a running string, means for releasably connecting said mandrel to said inner casing hanger, and means for rotating said second body section upon rotation of said mandrel, wherein said means for releasably connecting said mandrel to said inner casing hanger includes a left-hand threaded connection between said mandrel and said second body section, and said means for rotating said second body section includes releasable means for preventing initial right-hand rotation of said mandrel relative to said second body section and for permitting said right-hand rotation following initial left-hand rotation of said mandrel relative to said second body section.

4. In well bore casing apparatus for supporting an inner string of casing in an outer string of easing supported by an outer casing hanger providing a seat: an inner casing hanger including a first body section having a portion engageable with said seat, a second body section rotatable relative to said first body section and having means for connection with said inner casing string, packing means for forming a seal between said inner and outer casing hangers, a mandrel adapted for connec tion to a running string, means for releasably connecting said mandrel to said inner casing hanger, and means for rotating said second body section upon rotation of said mandrel, said means for releasably connecting said mandrel to said inner casing hanger includes a threaded connection between said mandrel and said second body section, and said means for rotating said second body section includes a member releasably coengaging said mandrel and said second body section and shiftable to a released position upon initial rotation of said mandrel in one direction relative to said second body section.

5. In well bore casing apparatus for supporting an inner string of casing in an outer string of casing supported by an outer casing hanger providing a seat: an inner casing hanger including a first body section having a portion engageable with said seat, a second body section rotatable relative to said first body section and having means for connection with said inner casing string, packing means for forming a seal between said inner and outer casing hangers, a mandrel adapted for connection to a running string, means for releasably connecting said mandrel to said inner casing hanger, and means for rotating said second body section upon rotation of said mandrel, said means for releasably connecting said mandrel to said inner casing hanger includes a threaded connection between said mandrel and said second body section, and said means for rotating said second body section includes a resilient ring, one of said mandrel and said second body section having a seat for said ring and an adjacent clearance space, said other of said mandrel and said second body section having shoulders engageable with opposite faces of said ring, said ring being interposed between one of said shoulders and said seat to prevent rotation of said mandrel relative to said second body section in one direction, and said other shoulder displacing said ring into said clearance space from said seat upon rotation of said mandrel relative to said second body section in the other direction to permit subsequent rotation of said mandrel relative to said second body section in said one direction.

6. In well bore casing apparatus for supporting an inner string of casing in an outer string of casing supported by an outer casing hanger providing a seat: an inner casing hanger including a first body section having a portion engageable with said seat, a second body section rotatable relative to said first body section and having means for connection with said inner casing string, packing means for forming a seal between said inner and outer casing hangers, a mandrel adapted for connection to a running string, means for releasably connecting said mandrel to said inner casing hanger, and means for rotating said second body section upon rotation of said mandrel, wherein said packing means includes a packing assembly having a resilient ring, means for supporting said packing assembly on one of said body sections for movement of said packing assembly to move said packing ring from a nonsealing position to a sealing position responsive to rotation of said mandrel, and means for releasably connecting said mandrel to said packing assembly for moving said packing assembly responsive to rotation of said mandrel.

7. Well bore casing apparatus as defined in claim 1, wherein said means for preventing axial movement between said sections includes radial surfaces on said first and second body sections rotatably supporting said second body section on said first body section.

8. Well bore casing apparatus as defined in claim 1, wherein said means for preventing axial movement between said sections includes radial surfaces on said first and second body sections rotatably supporting said second body section on said first body section, and further includes opposing cylindrical surfaces on said first and second body sections having opposing grooves thereon, and a ring in said opposing grooves for preventing axial separation of said body sections.

9. In well bore casing apparatus for supporting an inner string of casing in an outer string of casing supported by an outer casing hanger providing a seat: an inner casing hanger including a first body section having a portion engageable with said seat, a second body section rotatable relative to said first body section and having means for connection with said inner casing string, packing means for forming a seal between said inner and outer casing hangers, a mandrel adapted for connection to a running string, means for releasably connecting said mandrel to said inner casing hanger, and means for rotating said second body section upon rotation of said mandrel, wherein said first and second body sections are provided with radial surfaces rotatably supporting said second body section on said first body section, and including opposing cylindrical surfaces on said first and second body sections having opposing grooves thereon, and a ring in said opposing, grooves for preventing axial separation of said body sections, and spaced seal means completely isolating therebetween said radial surfaces and said grooves.

10. Well bore casing apparatus as defined in claim 1, wherein said means for preventing axial movement between said sections includes radial surfaces on said first and second body sections rotatably supporting said second body section on said first body section, and bearing means between said radial surfaces.

11. Well bore casing apparatus as defined in claim 1, wherein said means for releasably connecting said mandrel to said inner casing hanger includes fluid pressure operated means for releasing the same.

12. Well bore casing apparatus as defined in claim 1, wherein said means for rotating said second body section includes clutch means on said mandrel and said second body section.

13. Well bore casing apparatus as defined in claim 1, wherein said means for releasably connecting said mandrel to said inner casing hanger includes fluid pressure operated means for releasing the same, and said means for rotating said second body section includes clutch means on said mandrel and said second body section.

14. Well bore casing apparatus as defined in claim -1, wherein said means for releasably connecting said mandrel to said inner casing hanger includes an annular groove in said inner casing hanger, said mandrel having latch elements movable from projected positions in said groove to retracted positions, and fluid pressure operated means for holding said latch elements in said projected positions and allowing movement of said latch elements to said retracted positions.

15. Well bore casing apparatus as defined in claim 1, wherein said means for releasably connecting said mandrel to said inner casing hanger includes an annular groove in said inner casing hanger, said mandrel having latch elements movable from projected positions in said groove to retracted positions, said mandrel having a piston chamber therein, a piston reciprocable in said chamber, a part on said piston engageable with said latch elements to hold said latch elements in said projected positions when said piston is in one position and for allowing movement of said latch elements to said retracted positions upon movement of said piston to a second posiposition, and means for controlling the application of fluid under pressure to said chamber to move said piston.

16. Well bore casing apparatus as defined in claim 1, wherein said means for releasably connecting said mandrel to said inner casing hanger includes an annular groove in said inner casing hanger, said mandrel having latch elements movable from projected positions in said groove to retracted positions, said mandrel having a piston chamber therein, a piston :reciprocable in said chamber, a part on said piston engageable with said latch elements to hold said latch elements in said projected positions when said piston is in one position and for allowing movement of said latch elements to said retracted positions upon movement of said piston to a second position, and means for controlling the application of fluid under pressure to said chamber to move said piston including a bore in said mandrel, passages leading from said bore to said chamber at opposite sides of said piston, :and dart means engageable in said bore and having passages for establishing selective communication between said bore and said passages in said mandrel.

17. In well bore casing apparatus: an outer body connectable to an outer casing; an inner body supportable by said outer body for suspending an inner casing within the outer casing; said inner and outer bodies providing a fluid passage therebetween communicating with the annular space between the inner and outer casings; a packing structure for closing said passage; a mandrel adapted for connection to a running string; means releasably conmeeting said mandrel to said inner body; said inner body with the inner casing suspended therefrom and said packing structure being movable downwardly as a unit with said mandrel and running string to a position of support of said inner body on said outer body and with said packing structure in open relation to said passage; said inner body comprising relatively rotatable sections, means for efliecting rotation of one of said sections relative to the other section and said casing suspended from said inner body upon rotation of said mandrel; means for shifting said packing structure to a position closing said passage after rotation of said one of said sections of said inner casing on said outer body; means for effecting release of said mandrel from said inner body.

18. Well bore casing apparatus as defined in claim 17, wherein said means for effecting release of said mandrel from said inner body includes a threaded connection between said mandrel and said one of said body sections.

19. Well bore casing apparatus as defined in claim 17, wherein said means for effecting release of said mandrel from said inner body includes hydraulically operable latch means releasably connecting said mandrel to said one of said body sections.

20. In well bore casing apparatus for supporting an inner string of casing in an outer string of casing supported by an outer casing hanger providing a seat; an inner casing hanger including a first body section having a portion engageable with said seat, a second body section rotatable relative to said first body section and having means for connection with said inner casing string, means providing a fluid passage between said inner and outer casing hangers communicating with the annular space between the casing strings; packing means for forming a seal between said inner and outer casing hangers to close said passage, said packing means being disposed initially in a position opening said passage, a malfdrel adapted for connection to a running string, means for releasably connecting said mandrel to said inner casing hanger to permit said mandrel to be disconnected and removed from said inner casing hanger, means for rotating said second body section relative to said first body section upon rotation of said mandrel, and means for shifting said packing means into sealed relation with said inner and outer casing hangers to close said passage.

References Cited UNITED STATES PATENTS FOREIGN PATENTS Canada.

DAVE W. AROLA, Primary Examiner US. Cl. X.R. 

